From 3b1778314cb6ba2c2b55ced89dd5d87da88149cc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rn-Michael=20Miehe?= <jmm@yavook.de>
Date: Tue, 4 Apr 2023 23:06:31 +0000
Subject: [PATCH] namespace-inject: decorator class

---
 namespace-inject.py | 79 +++++++++++++++++++++++----------------------
 1 file changed, 40 insertions(+), 39 deletions(-)

diff --git a/namespace-inject.py b/namespace-inject.py
index 786b3c1..6293394 100644
--- a/namespace-inject.py
+++ b/namespace-inject.py
@@ -1,56 +1,53 @@
 import ast
 import inspect
 from textwrap import dedent
-from typing import Any, Callable
+from typing import Callable
 
 #################
 # MAGIC SECTION #
 #################
 
 
-def ast_dump(sobject) -> None:
-    print(f"Dumping AST of {sobject}")
-    print(ast.dump(ast.parse(
-        dedent(inspect.getsource(sobject)),
-    ), indent=4))
+class Shoehorn:
+    local_fns: tuple[Callable, ...]
 
+    def __init__(self, *local_fn: Callable) -> None:
+        self.local_fns = local_fn
 
-def shoehorn(f: Callable) -> Callable:
-    # ast_dump(f)
+    @staticmethod
+    def _get_func_def(object: Callable) -> tuple[ast.FunctionDef, ast.Module]:
+        object_ast = ast.parse(dedent(inspect.getsource(object)))
+        return next(
+            x for x in ast.walk(object_ast)
+            if isinstance(x, ast.FunctionDef) and x.name == object.__name__
+        ), object_ast
 
-    def foo() -> None:
-        print(f"{pstr = }")  # type:ignore # noqa: F821
+    def __call__(self, fn: Callable) -> Callable:
+        fn_func_def, fn_ast = self._get_func_def(fn)
 
-    # ast_dump(foo)
-    foo_ast = ast.parse(dedent(inspect.getsource(foo)))
-    foo_fn = next(
-        x
-        for x in ast.walk(foo_ast)
-        if isinstance(x, ast.FunctionDef) and x.name == "foo"
-    )
+        fn_func_def.body = [
+            self._get_func_def(lfn)[0]
+            for lfn in self.local_fns
+        ] + fn_func_def.body
 
-    class Shoehorn(ast.NodeTransformer):
-        def visit_FunctionDef(self, node: ast.FunctionDef) -> Any:
-            if node.name == f.__name__:
-                node.body.insert(0, foo_fn)
-                node.decorator_list = [
-                    decorator
-                    for decorator in node.decorator_list
-                    if not (
-                        isinstance(decorator, ast.Name)
-                        and decorator.id == shoehorn.__name__
-                    )
-                ]
-            return node
+        fn_func_def.decorator_list = [
+            decorator
+            for decorator in fn_func_def.decorator_list
+            if not (
+                isinstance(decorator, ast.Call)
+                and isinstance(decorator.func, ast.Name)
+                and decorator.func.id == Shoehorn.__name__
+            )
+        ]
 
-    f_ast = ast.parse(dedent(inspect.getsource(f)))
-    new_f_ast = ast.fix_missing_locations(Shoehorn().visit(f_ast))
-    # print(ast.dump(new_f_ast, indent=4))
+        if (fn_sourcefile := inspect.getsourcefile(fn)) is None:
+            fn_sourcefile = "<string>"
 
-    new_f_scope = {}
-    exec(compile(new_f_ast, "<string>", "exec"), new_f_scope)
-
-    return new_f_scope[f.__name__]
+        exec(
+            compile(fn_ast, fn_sourcefile, "exec"),
+            fn_globals := {},
+        )
+        return fn_globals[fn.__name__]
 
 ##################
 # NORMAL SECTION #
@@ -72,9 +69,13 @@ def func2(pstr: str) -> None:
     foo()
 
 
-@shoehorn
+def foo_local() -> None:
+    print(f"{pstr = }")  # type:ignore # noqa: F821
+
+
+@Shoehorn(foo_local)
 def func3(pstr: str) -> None:
-    foo()
+    foo_local()
 
 
 def func_info(f: Callable) -> None: